Use StringBuilder::appendLiteral() / StringBuilder::append(char) when possible

Source/core/fileapi/FileReaderLoader.cpp

 /*
  * Copyright (C) 2010 Google Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 364 matching lines @@
         builder.append(m_decoder->flush());
 
     m_stringResult = builder.toString();
 }
 
 void FileReaderLoader::convertToDataURL()
 {
     m_isRawDataConverted = true;
 
     StringBuilder builder;
-    builder.append("data:");
+    builder.appendLiteral("data:");
 
     if (!m_bytesLoaded) {
         m_stringResult = builder.toString();
         return;
     }
 
     builder.append(m_dataType);
-    builder.append(";base64,");
+    builder.appendLiteral(";base64,");
 
     Vector<char> out;
     base64Encode(static_cast<const char*>(m_rawData->data()), m_rawData->byteLength(), out);
     out.append('\0');
     builder.append(out.data());
 
     m_stringResult = builder.toString();
 }
 
 void FileReaderLoader::setEncoding(const String& encoding)
 {
     if (!encoding.isEmpty())
         m_encoding = WTF::TextEncoding(encoding);
 }
 
 } // namespace blink